- while (nbytes > walk->len_this_page) {
- memcpy_dir(buf, walk->data, walk->len_this_page, out);
- buf += walk->len_this_page;
- nbytes -= walk->len_this_page;
+ for (;;) {
+ unsigned int len_this_page = scatterwalk_pagelen(walk);
+ u8 *vaddr;
+
+ if (len_this_page > nbytes)
+ len_this_page = nbytes;
+
+ vaddr = scatterwalk_map(walk, out);
+ memcpy_dir(buf, vaddr, len_this_page, out);
+ scatterwalk_unmap(vaddr, out);
+
+ scatterwalk_advance(walk, len_this_page);
+
+ if (nbytes == len_this_page)
+ break;
+
+ buf += len_this_page;
+ nbytes -= len_this_page;